"The earth is the Lord's and everything in it..." Psalm 24:1
We do not own anything; everything belongs to God.
God appoints us as stewards over all that belongs to Him.
Whenever our hands of stewardship receive anything from the Lord, as it belongs to Him, we are to use it for His purposes and His glory.
As everything belongs to God, we are not to "give" a mere 10% of what He places in our hands of stewardship. Instead, we are responsible for making sure 100% of what God places in our hands of stewardship is allocated to that which He has ordained.
When God calls for us to transfer stewardship to others (to give away what belongs to God), we are to obey Him cheerfully and unbegrudgingly.
To be sure we are using 100% of what God has placed in our hands of stewardship for His purposes and His glory, we need to stay in close communion with God. When we are in close communion with the Lord, we will ask Him what we are to do with that which is His; and we will listen to and obey His promptings by relying on the power of the Holy Spirit to help us.